Weird elctrical problems 01 subbie

Out of nowhere the following things stopped working all at once:
Front and rear heater and ac controls, 2wd/4wd buttons , cruise control, prnd/odo, gas gauge, seat heaters, and warning indicator which just says BATTERY.
manual says that battery light is for bad alternator, but im charging 14v.
Well the battery finally died and was replaced.
Put new battery in, everything worked.
Until i try to turn on the heater fan.
Bad ground? Short? All fuses have been checked, or most all of them that seemed related.
Any clues?

Could be the start of a bad BCM.

Tester

1 Like

Definitely check all the grounds, plus both ends of both battery cables.

You might check the junction terminal which is located on the chassis near the battery positive terminal.
All electrical power except for the starter motor windings go through that terminal and over time scale can build up on the cable ends.

The heater fan is a high current draw item so if the problem is indeed in the junction terminal it could be that what little clean area there is for passing current is just not able to handle that high of a draw.

What happens when you try to turn on the blower? Do other things not work?